diff --git a/src/wp-includes/script-loader.php b/src/wp-includes/script-loader.php
index 96e26b0712..a0bbc5be06 100644
--- a/src/wp-includes/script-loader.php
+++ b/src/wp-includes/script-loader.php
@@ -355,8 +355,9 @@ function wp_default_scripts( &$scripts ) {
 	$scripts->add( 'mediaelement', false, array( 'jquery', 'mediaelement-core', 'mediaelement-migrate' ), '4.2.6-78496d1' );
 	$scripts->add( 'mediaelement-core', "/wp-includes/js/mediaelement/mediaelement-and-player$suffix.js", array(), '4.2.6-78496d1', 1 );
 	$scripts->add( 'mediaelement-migrate', "/wp-includes/js/mediaelement/mediaelement-migrate$suffix.js", array(), false, 1);
-	did_action( 'init' ) && $scripts->localize( 'mediaelement', 'mejsL10n', array(
-		'language' => get_bloginfo( 'language' ),
+
+	did_action( 'init' ) && $scripts->add_inline_script( 'mediaelement-core', sprintf( 'var mejsL10n = %s;', wp_json_encode( array(
+		'language' => strtolower( str_replace( '_', '-', is_admin() ? get_user_locale() : get_locale() ) ),
 		'strings'  => array(
 			'mejs.install-flash'       => __( 'You are using a browser that does not have Flash player enabled or installed. Please turn on your Flash player plugin or download the latest version from https://get.adobe.com/flashplayer/' ),
 			'mejs.fullscreen-off'      => __( 'Turn off Fullscreen' ),
@@ -443,7 +444,7 @@ function wp_default_scripts( &$scripts ) {
 			'mejs.welsh'               => __( 'Welsh' ),
 			'mejs.yiddish'             => __( 'Yiddish' ),
 			),
-		) );
+		) ) ), 'before' );
 
 
 	$scripts->add( 'mediaelement-vimeo', "/wp-includes/js/mediaelement/renderers/vimeo.min.js", array('mediaelement'), '4.2.6-78496d1', 1 );